The Titanium Main Shaft/CNC Delrin Main Gear/Auto-Rotation Hub set is specifically designed with Solid Titanium One-way Main Shaft, Adjustable Colar and Auto-Rotation Hub to optimize for stability, durability and overall performance of the WALKERA MASTER CP helicopter. This new design utilizes high-end CNC machining, to produce tight and accurate tolerances throughout the part set, from Solid Titanium, Aluminum, Delrin, Stainless Steel and Brass materials. With the perfect match of the Solid Titanium One-way Main Shaft, Adjustable Colar and Auto-Rotation Hub, the Titanium Main Shaft/CNC Delrin Main Gear/Auto-Rotation Hub set dramatically keeps reduced vibration when Motor increases or reduces speed suddenly during 3D flight, for a strong, smooth and durable running. More than that, in case that the supply of power is failed unexpectedly, this new upgrade keeps Main Blades rotating automatically to the initial inertia until a point of time to stop. So the helicopter will be landed safely in the best condition, instead of falling down suddenly. Besides, using Lower Main Shaft Colar to hold One-way Main Gear Hub makes it easier to upgrade or replace. The Titanium Main Shaft/CNC Delrin Main Gear/Auto-Rotation Hub set will be an integral part of your WALKERA MASTER CP helicopter and brings further developments in high-performance. Included: 1 x Titanium Main Shaft/CNC Delrin Main Gear/Auto-Rotation Hub set Hardwares Usage: Use for WALKERA MASTER CP Requires: Read and follow the Assembly Instruction carefully Loctite (#242 is recommended) is required to apply to all mechanical screws for safety precaution Basic hand tools Instruction: Manual and Instruction included